The present invention relates generally to monitoring systems and methods. More particularly, one embodiment of the present invention relates to a system for and method of establishing monitoring alarm limits based on physiological variables.
In general, alarm systems of physiologic monitors support two attributes of clinicians: vigilance and decision making. Of these two attributes, a monitor""s alarms are especially needed for vigilance since clinicians, as humans, are relatively poor at this task. An alarm should vigilantly wait for an ominous change in the patient""s condition, correctly notifying the clinician of that change. A secondary function of an alarm is to point to the origin of the problem that caused the alarm. Ample research shows that current alarm systems fail in both measures. See, for example, Keenan, R. L. xe2x80x9cAnesthetic disasters: incidence, causes, preventability.xe2x80x9d American Society of Anesthesiologists. ASA annual refresher course lectures, 221 (1987): 1-6; Lunn, J. N. and H. B. Devlin. xe2x80x9cLessons from the confidential inquiry into peri-operative deaths in three NHS regions.xe2x80x9d Lancet 2 (1987): 1384; Koski, E. M., A. Mxc3xa4kivirta, T. Sukuvaara and A. Kari. xe2x80x9cClinicians"" opinions on alarm limits and urgency of therapeutic responses.xe2x80x9d International Journal of Clinical Monitoring and Computing 12 (1995): 85-88; and Meredith C. and J. Edworthy. xe2x80x9cAre there too many alarms in the intensive care unit? An overview of the problems.xe2x80x9d Journal of Advanced Nursing 21.1 (1995): 15-20.
While simple threshold alarm systems currently employed in physiologic monitors are vigilant, these alarms are often spurious. For example, conventional alarms will sound the moment a physiologic variable exceeds the threshold set for it. Although the alarm is reliably triggered when it was instructed to, often there is no justification for the alarm. In one study, researchers surveyed the problems with alarms in intensive care units, citing excessive false alarms among other problems. Meredith C. and J. Edworthy. xe2x80x9cAre there too many alarms in the intensive care unit? An overview of the problems.xe2x80x9d Journal of Advanced Nursing 21.1 (1995): 15-20.
In a survey of alarms at a children""s hospital intensive care unit (ICU), researchers found after 298 monitored hrs, 86% of a total 2,942 alarms were found to be false-positive alarms, while an additional 6% were classified as clinically irrelevant true alarms. See, Tsien, C. L. and J. C. Fackler. xe2x80x9cPoor prognosis for existing monitors in the intensive care unit.xe2x80x9d Critical Care Medicine 25 (1997): 614-619. Only 8% of all alarms tracked during the study period were determined to be true alarms with clinical significance.
A study of alarms in the anesthesia environment showed 40-75% of alarms in the anesthesia environment are false. See, Mylrea, R. A., J. A. Orr and D. R. Westenskow. xe2x80x9cIntegration of monitoring for intelligent alarm in anesthesia: neural networksxe2x80x94can they help.xe2x80x9d Journal of Clinical Monitoring 9 (1993): 31-37. From another perspective, other researchers found that only 7% of anesthesia-based alarms turned out to be useful. Meijler, A. P. xe2x80x9cAutomation in anesthesiaxe2x80x94a relief?xe2x80x9d Berlin: Sprinter-Verlag, 1987. In a survey of 852 anesthesiologists, researchers determined that 58% of respondents had disabled all alarms at the beginning of a case and that 25% did so routinely. See, McIntyre, J. W. xe2x80x9cErgonomics: Anaesthetists"" use of auditory alarms in the operating room.xe2x80x9d International Journal of Clinical Monitoring and Computing 2 (1985): 47-55.
Conventional alarm systems of physiologic monitors are weak because they exhibit a high false positive rate and when alarms are true positives they are often clinically irrelevant. Alarm limits used in such conventional alarm systems are based generally on only clinical experience and/or approximations. Such alarm limit approximations are often overly inclusive, resulting in high incidents of false positive or clinically irrelevant alarms. Whatever improvements to an alarm system are made, clinicians must be able to use them on patients on a day-to-day basis in a way that improves patient care.
Thus, there is a need for an alarm system for physiologic monitors which provide more accurate alerts. Further, there is a need for an accurate alarm system for physiologic monitors which is commercially viable. Even further, there is a need for determining more appropriate alarm limits for a physiologic monitor, resulting in more meaningful alarms.
The teachings hereinbelow extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the above-mentioned needs.
The present invention relates to a method and system for establishing monitoring alarm conditions based on system variables. This system or method can include receiving a plurality of system variable data where the system variable data is representative of system acceptability variables, correlating alarm states of the system acceptability variables with alarm states of the system measurable variables, and providing a best clinical selection for the alarm limits.
One exemplary embodiment of the invention is related to a method of establishing monitoring alarm limits based on physiological variables. This method can include the steps of receiving a plurality of physiological variable data where the physiological variable data is representative of physiological wellness variables, correlating alarm states of the physiological wellness variables with alarm states of the physiological measurable variables, and providing a best clinical selection for the alarm limits.
Another exemplary embodiment of the invention is related to a computer implemented method of establishing alarm limits for a physiological monitor. The physiological monitor is configured to monitor measurable variables of a patient. This method can include associating alarm states of wellness physiological variables with measurable physiological variables, providing a range of acceptable alarm limits based on the associated alarm states, and selecting monitor alarm limits for a physiological monitor based on the provided range of acceptable alarm limits.
Another exemplary embodiment of the invention is related to a system for establishing monitoring physiological alarm limits based on calculated physiological variables. This system can include means for receiving a plurality of physiological variable data where the physiological variable data is representative of physiological wellness variables, means for correlating alarm states of the wellness physiological wellness variables with physiological measurable variables, and means for providing a best clinical selection for the alarm limits.
Another exemplary embodiment of the invention relates to a method of establishing monitoring alarm limits based on system variables. This method can include the steps of receiving a plurality of system variable data where the system variable data is representative of system acceptability variables, correlating alarm states of the system acceptability variables with alarm states of system measurable variables; and providing a manufacture determined selection for the alarm limits.
Another exemplary embodiment of the invention relates to a computer implemented method of establishing alarm limits for a monitor where the monitor is configured to monitor measurable variables of a system. This method can include associating alarm states of system acceptability variables with alarm states of system measurable variables, providing a range of acceptable alarm limits based on the associated alarm states, and selecting monitor alarm limits for a monitor based on the provided range of acceptable alarm limits.
Other principle features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims.